Review: Lehmann Audio Rhinelander headphone amplifier

The headphone amplifier is, undoubtedly, one of the most underrated electronic devices. It’s hardly surprising as we don’t often see the point in placing a device and additional cables between a source and a set of headphones, especially if it alters the original signal. Why then use a headphone amplifier when any integrated amplifier, mini-stereo system, CD player or USB DAC is already fitted with one? We’re going to try and answer this question by presenting the Lehman Audio Rhinelander.

What’s the point of having an external headphone amplifier?

The answer isn’t as straightforward as you’d imagine. Yes, the aim of the headphone amplifier is to increase audio signal intensity to offer listeners a more comfortable listening volume, but that’s not all. To fully understand what a headphone amplifier brings to the delivery of music, you must see it as a stack of layers/sound levels in at least two dimensions ? width and depth. With an integrated headphone amplifier (smartphone, portable device, integrated amplifier, television, etc.), these sound levels have a tendency to get tighter and become tangled the more you turn up the volume. If you add the accompanying distortion, listening becomes aggressive and tight. You get the overriding impression that all recordings sound the same.

A good headphone amplifier can ?spread out? sound levels, give space to those with micro information, in order to offer a realistic sound delivery, with a sensation of space. You will immediately hear unsuspecting details and certain sounds will be perceived in a new light, notes will sound clearer, you will hear the artist breathing, the echo, etc.

Presentation

The Lehmann Audio Rhinelander is the German brand’s entry level model. It is, however a resolutely audiophile, hand-made device, which uses high-quality MKP capacitors and other components rarely seen on a model of this price.

The back panel features two RCA-Cinch analog stereo inputs along with an external power supply. On the front panel, there is a Neutrik format headphone output (6.35 mm jack), a volume potentiometer and a selector switch. This switch allows the second analog input to be transformed into a pre-out output, to run a power amplifier for example. The headphone output is then logically bypassed. The power supply is a small switching model.

The second input can be transformed into a pre-out output for a power amplifier

The connectors are labeled underneath the device

Test configuration

We listened to the Lehmann Audio Rhinelander with two very different sets of headphones ? one set, an orthodynamic model, the HiFiMAN HE-500 and the other, an entry-level dynamic model, the Sennheiser PX-100. Two sources were paired up with Rhinelander: the Arcam rPAC USB DAC and the Graham Slee Bitzie USB. The entire set-up was interconnected with Viard Audio Premium HD RCA cables and an Audioquest Coffee USB cable. We used Foobar2000 in Wasapi mode to listen to FLAC files on our PC. Suffice to say that the Lehmann Audio Rhinelander was placed in a coherent configuration.

Listening impressions

The first impression is that of a very smooth sound delivery. The sound signature of each DAC is respected. Listening is serene. The different sound levels are exposed and the stereo is clearly defined. The rising and falling time of notes seem to be better controlled and the sound is faster, with everything seeming to be more peaceful. We increase the volume without fearing a full-on sound attack.

The Lehmann Audio Rhinelander headphone amplifier immediately favours the bass and low-medium ranges on signals which require a lot of electric intensity in order to be delivered with precision and realism. The Rhinelander never seems short-winded. It successfully handles harsh sonority, never letting an instrument go beyond its individual partition.

With so much control, we had great fun listening to tracks which would normally be considered aggressive or unbalanced.

The Lehmann Audio Rhinelander paired with the Arcam rPAC should delight those with weak bass-sounding headphones

You Got It, Roy Orbison (FLAC 16/44)

The artist’s velvet-smooth vocals surf over the acoustic guitar, which is itself never drowned out by the rhythm section or electric guitar. The male backing vocals are also well placed.

Is it a Crime – Lovers Live, Sade (FLAC 16/44)

The bass drum is simply stunning during the introduction and throughout the song when played on the Bitzie. The bass guitar emphasises each impact. Without the aid of the Rhinelander, neither the Bitzie nor rPAC strike so hard.

No Ordinary Love, Sade (FLAC 16/44)

Surprise…the prominent bass line isn’t as overpowering as initially expected but the sound is mostly concentrated in Sade’s voice, which rings out with an unfamiliar reverb.

Paranoid Android, Radiohead (FLAC 16/44)

The rich mix of this track is delivered with detail and fury. We would prefer more impact for the bass drum. It is however lacking in unity, probably due to our entry and mid-range level DACs.

Blizzard, Fauve (FLAC 16/44)

An excellent test to assess medium frequency articulation. The Rhinelander pays homage to Quentin Postel’s diction and breathing. We like it.

Game of Thrones Main Title, Ramin Djawadi (FLAC 16/44)

Is the original mix in 5.1? Sound levels seem to be too close to each other and the placing of instruments doesn’t meet the acoustic requirements of a large room. The Lehmann Audio Rhinelander partition is a bit dull.

Oh how it goes down so low! This type of test on a highly compressed sound take is always interesting. Stromae’s voice is simply magnificent to listen to during this live session. The Rhinelander does a great job in dissecting the rhythm section.

Striking advantages in HD listening

The sound here literally hits us. Daft Punk’s Random Access Memories in Qobuz version (FLAC 24/88.2) is quite simply amazing! The Lehmann Audio Rhinelander provides real density to this album whose surface we’d only scratched up until now. The Game of Love is so powerful, our eardrums almost explode. Giorgio Moroder’s interview throughout Giorgio by Moroder is extremely clear, every breath he takes is perceptible. On their own, the DAC Arcam rPAC and the Graham Slee Bitzie cannot offer as much room for sound. The last two minutes of the track are a festival of snare drum with and deliver an incredible energy. It’s a real aural assault. The intro to Lose Yourself to Dance literally crackles, the drummer madly beats the drum for our maximum listening pleasure while Pharell Williams’ voice easily finds its place.

Conclusion

The Lehman Audio Rhinelander headphone amplifier really impressed us. Its USB DAC support is clear: scale, great sound placement, powerful and detailed bass…to name but a few of its assets. If you thought that a headphone amplifier would only damage the audio signal, the result is the exact opposite. The music coming from the Lehmann Audio Rhinelander is totally over-energised and listening is less aggressive. Whether you own headphones with an impedance of 300 Ohms or 16 Ohms, you’ll enter a completely new musical universe.

The quality of interconnect cables is a determining factor with a headphone amplifier. Viard Audio Premium HD RCA-RCA cables proved themselves to be admirably neutral during our listening sessions.